1079771991 has 4 divisors (see below), whose sum is σ = 1439695992. Its totient is φ = 719847992.

The previous prime is 1079771977. The next prime is 1079772049. The reversal of 1079771991 is 1991779701.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1079771991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1079771951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179961996 + ... + 179962001.

It is an arithmetic number, because the mean of its divisors is an integer number (359923998).

Almost surely, 2^1079771991 is an apocalyptic number.

1079771991 is a deficient number, since it is larger than the sum of its proper divisors (359924001).

1079771991 is an equidigital number, since it uses as much as digits as its factorization.

1079771991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359924000.

The product of its (nonzero) digits is 250047, while the sum is 51.

The square root of 1079771991 is about 32859.8842207333. The cubic root of 1079771991 is about 1025.9133610900.

The spelling of 1079771991 in words is "one billion, seventy-nine million, seven hundred seventy-one thousand, nine hundred ninety-one".